Morbid obesity is a chronic condition. Gastric limiting techniques (e.g. “adjustable gastric banding” or AGB) are employed by surgeons to treat morbidly obese people who cannot lose weight by traditional means. In AGB, a gastric “band” made of an elastomer is placed around the stomach near its upper end. This creates a small pouch with a narrow passage into the rest of the stomach (“stoma orifice”), thus limiting the amount of food intake (“eating”) by creating a feeling of fullness or uneasiness and by usually extending the time frame required to empty the pouch into the rest of the stomach. To control the size of the stoma orifice, the gastric band can be pressurized or depressurized by a physician. As a non-limiting example, the pouch is usually of a size of 50 cc to 5 cc, preferably 20 cc to See, and more preferably of about 15 cc. The stoma size can be increased or decreased with a saline solution by using a needle and syringe to access a small access port placed under the skin. The stoma orifice is governed by the amount of stomach tissue inside the band at the banding site. A desired passage size is about 12 mm in internal diameter.
The aim of restricting passage of food and liquids is to force the patient to change his/her eating behavior and thereby to induce a significant amount of weight loss. Researchers have demonstrated that the initial weight loss results after AGB are less predictable then those after gastric bypass. Patients after surgery are advised to chew their food thoroughly, eat slowly, take small bites, avoid certain foods, etc. Often, a large number of these patients do not adopt the required behavior and instead, eat forcefully, vomit, and intermittently suffer stoma occlusion events. These may result eventually in such complications as pouch enlargement, band erosion, reflux, and esophageal enlargement. In some cases, additional surgical interventions may be required.
The observation of gastric band action and the adjusting of stoma orifice by inflation/deflation are facilitated by X-ray imaging. A physician or technician acts to adjust (increase or decrease) the volume of fluid in the band based on inputs from the X-ray imaging. The volume decrease is done by removing an amount of fluid from the band via the external access port and fill line. Alternatively, components for adjusting the size of the gastric band may be implanted within the patient and, when a physical parameter such as intra-band pressure related to the patient food passage is determined, an external control unit outside the patient's body may be operated to power the implanted components to adjust the size of the band.
Monitoring the activity of the pouch created between the lower esophagus sphincter and the gastric band may generate important information related to the eating behavior of patients. Physiological parameters obtained by such monitoring may be useful to help a patient control his/her obesity, manage his/her diabetes, and monitor his/her gastro-esophageal reflux disease and the like.
Adjustable gastric restriction devices with sensors and actuators which enable control of the stoma orifice are disclosed for example in US patent applications No. 20070156013 by Birk and 20060173238 by Starkebaum. Birk discloses a self-regulating gastric band with pressure data processing, relates to a band adjustment assembly which is provided for implanting with the gastric band that includes a sensor for sensing fluid pressure in the expandable portion. The band adjustment assembly further includes a pump assembly connected to the expandable portion and to a controller that can operate the pump assembly to adjust the volume of the fluid in the band based on the sensed fluid pressure. Starkebaum's invention relates to a dynamically controlled gastric occlusion device that monitors at least one physiological parameter that varies as a function of food intake and controls the degree of gastric constriction of an occluding device, such as a gastric band, based on the monitored physiological parameter. In an embodiment, the dynamically-controlled gastric occlusion device controls the degree of gastric constriction based on time. The occluding device is dynamically opened or closed to either permit or prevent the passage of food through the gastrointestinal (GI) tract.
A large number of studies have determined the following:                1) Pouch volume and stoma size are important determinants for the success of AGB.        2) Proper stoma adjustment can effect immediate and late results of the AGB and reduce complications such as Spherical Pouch Dilatation (SPD).        3) Fast eating or improper chewing of the food can lead to excessive pouch enlargement and impaired surgical results.        4) Adoption of favorable eating behavior is imperative for long term success of the AGB        5) Adoption of mal-eating behaviors can reduce the success rate of AGB.        
Although gastric bands can limit food intake, it is worth recognizing that eating is a form of behavior that can be defined according to its structure (frequency duration and size of eating episodes). This pattern of behavior can be further analyzed at the level of a single meal, where the same structure (frequency duration and size of eating episodes—bites) rules and defines the meal size. In principle, this behavior operates through the skeletal musculature and is subject to conscious control. Therefore, people should be able to volitionally decide when and how to control their own eating. In practice, people find it extremely difficult to exert control and many obese people claim that their eating is out of (their) control.
AGB or other bariatric procedures such as: Gastric-By-Pass, Sleeve Gastrectomy, Vertical Banded Gastroplasty and Duodenal Switch, these procedures are not known to provide a patient with data or information regarding his/her eating behavior pattern, yet the patient is expected to adopt different eating behavior with respect to frequency, duration or size of bite or meal. The realization and visualization of eating behavior patterns is required to the patient in order to induce conscious and correct eating behavior modification. Therefore there is a need for a tool that will provide the AGB and other bariatric procedures obese patients a guided and controlled eating monitoring system and/or “pacer” that will enable them to learn and gain a new control over their eating behavior.
Out of the clinical literature from the last 15 years and over 500,000 patients with AGB it is clear that it is very difficult to obtain hard quantitative data on the true food intake behavior of AGB or other bariatric procedures obese patients. It is clear that in some AGB obese individuals, habitual food intake or its caloric value are greater than it is normally assumed to be and is often erratic and apparently unregulated. In order for health care givers to be able to advice and guide those patients to better regulate eating habits and behavior, there is clearly a need for a method and apparatus that will enable them to monitor and obtain objectively recorded eating behavior patterns. It would also be advantageous to have systems and methods to improve the action of AGB or other patients post bariatric procedures by automatically releasing excessive pressure buildups.
Fried, Surgery of Obesity and related diseases (2008 May-June) described the current science of gastric banding: “an overview of pressure-volume theory in band adjustments”.
Fried et al in Obesity Surgery, 14, 2004 1121 measured intra band pressure on human subjects, using water as the swallowed medium, under fluoroscopy. In this study, the aim was to establish and compare stoma size and calibration with a low pressure-high, volume system, and a high pressure low volume system. The gastric space was towards the balloon of the band, which is responsible for stoma diameter maintenance. Pressure measurements were made in a patient with a low pressure-high volume band (SAGS), with baseline pressure of 40 mmHg There was an increase in pressure at the stoma region of up to 85 mmHg following a sip of water. A similar experiment is described by Fried et al in Obesity Surgery (2010 August) “The relationship between esophageal peristalsis and in vivo intraband pressure measurements in gastric banding patients”.
Lechner at al describes in vivo band manometry as a new access to band adjustment focusing on optimal stoma size using a manometry, vs. volume calibration. (Obesity Surgery (2005 November-December).
Obrian et al in J Clin Endocrinol Metab, February 2005, 90(2):813-819, conducted measurements in human subjects for optimal band restriction. This study demonstrated that both fasting and postprandial feelings of satiety were significantly increased with optimal LAGB restriction compared with 2 days of reduced LAGB restriction. Importantly, these appetite changes were recorded within days in weight-stable individuals who had achieved significant weight loss, were the same weight at both tests, were blind to their band status, and after 14 h of fasting. Optimally restricted LAGB participants were also less hungry than BMI-matched controls. These findings strongly support the hypothesis that LAGB exerts an inhibitory effect on central appetite regulation, operating even during fasting.
Tavori. I, Fleicsher. L (WO/2009/050709) PCT/IL2008/001366 Apparatus and methods for corrective guidance of eating behavior after weight loss surgery is dealing with measuring influence of different food type on band pressure describe a device, system and method of providing corrective guidance to patients, post weight loss surgery using intraband pressure measurements.
However all of these depend on interpretation of the data by the clinician and therefore do not allow self-monitoring by the patient.
It is therefore a long felt need to provide a system and method of enabling the clinician and/or the patient to provide guidance to the patient on modifying eating habits.